This invention relates to a method and apparatus for sensing indicia on an object and, more particularly, to sensing if indicia are present or absent at selected locations, or zones, on the object.
It often is necessary during high-speed automated processing and manipulation of various objects to verify that such automated processing is proceeding properly. In some applications, indicia are printed or otherwise provided on objects which subsequently are handled for various purposes. In the environment of automated mail handling systems, for example, pre-addressed envelopes may be conveyed and passed rapidly through a printer which operates to print various additional indicia on those envelopes. For instance, bar codes representing zip codes may be printed on the envelopes; these bar codes being sensed by postal service equipment for the rapid classification of mail by zip code destination. Other indicia also may be printed on the envelopes for the purpose of providing sorting of mailing pieces, postage discounts and record keeping, all associated with rapid processing of large volumes of mail.
In the aforementioned environment, indicia are printed at various select locations on the envelope by high-speed mail-handling equipment. To assure the correct operation of such equipment, it is important to verify that indicia are, in fact, printed at those selected locations. Indeed, it may be as important to verify the presence of indicia as to interpret that indicia.
A desirable feature of automated mail-handling equipment is to permit the utilization thereof by individuals who need not necessarily possess high technical skills. Advantageously, indicia verifying equipment of the aforementioned type should be adaptable to accommodate envelopes of various sizes and shapes, and should be further adaptable for use with different sets of envelopes wherein one set may be provided with indicia at one location thereon while, in another set, that same location may be provided with no indicia.
The problems associated with automated mail-handling equipment also may be found with other high-speed equipment which manipulate other types of objects, such as printed documents, coded containers, marked assembly parts, tagged baggage and the like. A common difficulty in all of these is that, in the absence of indicia located at correct, predetermined position on an object, significant economic effects may result. Typically, object-handling apparatus, such as conveyor belts, transport equipment and other associated devices, may have to be shut down to isolate the cause of failure to provide such indicia. A more serious disadvantage may result in an entire run of envelopes, documents, containers or other manipulated objects being rejected or disqualified because of the absence of indicia at the correct locations. It will be appreciated that it is highly inefficient and expensive to initiate another run or to substitute for the disqualified or rejected objects.
It has become acceptable in automated mail-handling equipment to provide then Postal Service with a manifest of mail pieces (e.g. envelopes) which summarizes the number of pieces directed to specific zip code destinations, and to bundle such pieces to facilitate further processing by the Postal Service. To correlate such mail pieces with the manifest, informational indicia and, in many instances, coded indicia (such as bar codes) are provided on each envelope. In return for the marking of these mail pieces and for the manifest therefor, the Postal Service grants discounts in the established postage rates to those who comply with the particular regulations associated with this discounted service. However, in the absence of the agreed upon indicia on the mail pieces, users may forfeit the discounts to which they otherwise might be entitled, and may even be subject to various monetary penalties.
Thus, there is a need to provide a system by which objects in general, and mail pieces in particular, may be verified as having indicia provided at the correct locations thereon. Additionally, and with specific reference to automated mail-handling equipment and other high-speed document handling devices, there is an added benefit if the system which verifies the presence of indicia on an object also functions to anticipate possible jams which may develop in the handling equipment. For example, if successive envelopes or documents overlap, not only will indicia not be sensed on the underlying envelope (or document), but the overlap may cause a jam or other misoperation in the mail-handling (or document-handling) equipment.